"At four weeks out, trailer search volume on Google coupled with both the franchise status of the movie and seasonality can predict opening weekend box office revenue with 94% accuracy."

According to Google, the more people searching for a specific movie, the bigger the box-office weekend.

More people are searching for movies during the one-week window prior to, during, and after it's release.

The key for box-office success doesn't only lie in movie searches, but also in search ad click volume.

"In the seven day window prior to a film’s release date, if one film has 250,000 more search queries than a similar film, the film with more queries is likely to perform up to $4.3M better during opening weekend. When looking at search ad click volume, if a film has 20,000 more paid clicks than a similar film, it is expected to bring in up to $7.5M more during opening weekend."

In addition, Google's report says YouTube searches are also a strong predictor of opening-weekend performance.

According to the study, marketers should be looking at movie title searches on YouTube a month before a movie release, not just the week of because that's when they'll "have the highest predictive power."

Another takeaway: for the most part, unless it's a big release, moviegoers have no clue what is coming out at theaters until it's about to come out.